1. Field
The present application relates to a semiconductor device, an information control method and an electronic device.
2. Description of the Related Art
In terms of ensuring security of hardware or software, greater tamper-proof capability is desired, so as to prevent the inside of the hardware or the software from being analyzed or falsified. In the field of semiconductor devices, the prevention of unauthorized write operations carried out on a semiconductor device by unauthorized persons is necessary. For example, unauthorized write operations by unauthorized persons may be prevented by controlling a switching operation between a mode, in which information is written to the semiconductor device, and the other mode, in which the written information to perform a desired operation is read from the semiconductor device.
Japanese Laid-open Patent Publication No. 2004-245060 discusses that one or more non-disclosed connector terminals is/are added separate from disclosed connector terminals used for inputting write enable/disable signals to a rewritable non-volatile memory.
Since a semiconductor device enters a write mode only when all the signals are correctly input to both the disclosed and non-disclosed connector terminals in the typical technique discussed above, a write operation to the rewritable non-volatile memory is not executed in the above case.
In the typical technique, a control signal is input to the non-disclosed connector terminal(s) for controlling a write operation to the semiconductor device.
Consequently, if the non-disclosed connector terminal(s) is/are detected by an unauthorized person, the control signal is input thereto, so that an unauthorized write operation to the semiconductor device may be carried out. Hence, the typical technique is unable to prevent the unauthorized write operation by the unauthorized person, in the above case.